冻融循环和碳化作用下面板混凝土的耐久性研究

张书华; 祁志强; 谭光荣; 张治军; 徐谋; 陈博夫; 田斌

doi:10.13928/j.cnki.wrahe.2025.11.019

水利水电技术（中英文） ›› 2025, Vol. 56 ›› Issue (11) : 243 -254. DOI: 10.13928/j.cnki.wrahe.2025.11.019

水工材料

冻融循环和碳化作用下面板混凝土的耐久性研究

张书华 ¹^,² ,
祁志强 ¹^,² ,
谭光荣 ¹^,² ,
张治军 ¹^,² ,
徐谋 ¹^,² ,
陈博夫 ³ ,
田斌 ³

作者信息 +

Study on durability of face slab concrete under freeze-thaw cycle and carbonation

Shuhua ZHANG ¹^,² ,
Zhiqiang QI ¹^,² ,
Guangrong TAN ¹^,² ,
Zhijun ZHANG ¹^,² ,
Mou XU ¹^,² ,
Bofu CHEN ³ ,
Bin TIAN ³

Author information +

文章历史 +

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摘要

【目的】针对我国北方地区堆石坝面板的实际服役环境，冻融条件下碳化耐久性失效是导致寒冷地区面板混凝土耐久性劣化的主要问题。为探究冻融循环对面板混凝土碳化耐久性的影响规律及机理，【方法】采用快速冻融试验、加速碳化试验、扫描电镜及核磁共振分析技术，对混凝土试件进行0次、50次、100次、150次、200次冻融循环，再加速碳化0 d、7 d、14 d、28 d。通过对混凝土碳化深度、相对动弹性模量、超声波波速、劈裂抗拉强度、抗压强度等宏观指标及孔隙率、孔径分布等微观指标的测试，分析了冻融循环和碳化作用对混凝土微细观孔隙结构及耐久性的影响规律。【结果】结果表明：冻融损伤条件下，碳化作用后混凝土的碳化深度大于单独碳化作用下的碳化深度；碳化作用提高了面板混凝土的相对动弹性模量、超声波波速、劈裂抗拉强度及抗压强度。冻融循环200次后，碳化28 d的最可几孔径由59.35 nm减小为41.94 nm,降低了29.33%。【结论】冻融循环对混凝土造成的损伤，降低了混凝土的抗碳化能力；碳化反应降低了面板混凝土的孔隙率及最可几孔径，缓解了冻融循环对混凝土造成的损伤。控制混凝土内孔径d>1 000 nm孔径范围孔含量，增加10 nm≤d<100 nm范围内孔的含量，可以提高冻融条件下面板混凝土的抗碳化耐久性。

Abstract

[Objective] According to the actual service environment of the face slab of rockfill dam in northern China, the failure of carbonation durability under freeze-thaw conditions is the main problem leading to the deterioration of the durability of face slab concrete in cold areas. In order to explore the influence law and mechanism of freeze-thaw cycles on carbonation durability of face slab concrete, [Methods]the rapid freeze-thaw test, accelerated carbonation test, scanning electron microscope and nuclear magnetic resonance analysis technology were used to conduct freeze-thaw cycles on concrete specimens for 0, 50, 100, 150 and 200 times, and then accelerate carbonation for 0, 7, 14 and 28 days. By testing the macro indexes of concrete such as carbonation depth, relative dynamic elastic modulus, ultrasonic wave velocity, splitting tensile strength and compressive strength, and micro indexes such as porosity and pore size distribution, the influence of freeze-thaw cycle and carbonation on the micro-pore structure and durability of concrete is analyzed. [Results] The results show that the carbonation depth of concrete after carbonation is greater than that under the condition of freeze-thaw damage. Carbonization improves the relative dynamic elastic modulus, ultrasonic wave velocity, splitting tensile strength and compressive strength of concrete face slab. After 200 freeze-thaw cycles, the most probable pore size of carbonization for 28 days decreased from 59.35 nm to 41.94 nm, a decrease of 29.33%. [Conclusion] The damage caused by freeze-thaw cycle to concrete reduces the carbonation resistance of concrete; Carbonization reaction reduces the porosity and the most probable pore size of face slab concrete, and alleviates the damage to concrete caused by freeze-thaw cycle. Controlling the pore content in the range of concrete internal pore diameter d>1 000 nm and increasing the pore content in the range of 10 nm≤d<100 nm can improve the carbonation resistance of face slab concrete under freezing and thawing conditions.